Typical heating, ventilation, and air conditioning (HVAC) machines require annual or semi-annual checking in order to ensure that they continue to operate efficiency. In traditional reactive maintenance methods, field engineers fix problems after faults are detected. Due the complexity of the system and other limitations, when the faults are found, the system energy performance is often already degraded from its normal level and significant energy has been wasted.
Today's common practice is “paper and pencil” based fixed schedule maintenance, which mainly relies on the experience of engineers responsible for maintaining the machines. Mechanic engineers often need to check and maintain the machines based on name plate (e.g., a sticker) on the surface of the equipment. The run time sensor data are trended from a control system, often stored in vendor-specific database. In theory, it is important to combine the name plate information and the historical trending data in order to estimate the wear and tear of a specific machine. However, in practice, field engineers often make decisions based on the limited information on the name plates and their experiences. Thus, engineers are operating on limited information which results in inefficiencies and imprecision in machine maintenance.